每个sql语句都它的执行计划，并且执行计划会放在plan_table中，plan_table中有object_name一列，该列表示sql语句中的对象名字，执
原理：
每个sql语句都它的执行计划，并且执行计划会放在plan_table中，plan_table中有object_name一列，该列表示sql语句中的对象名字，执行计划对表很感兴趣，所以如果object_type=’table’,那么object_name就是我们要截取的table_name
执行步骤：
1、创建tmp_table 表，存放job名job_id,sql语句select_sql,和表名object_name
create table tmp_table(job_idvarchar2(50),select_sql clob,object_name varchar2(50));
模拟数据：
a job中是一条比较短的sql语句       
b job中是一条比较长的sql语句 
insertinto tmp_table vlaues(‘a’,q’[a中的内容]’);
insertinto tmp_table vlaues(‘b’,q’[b中的内容]’);
commit;
2、创建p存储过程,根据执行计划
--以下是用4000以下的a job和4000 以上的b一起运行
create or replace procedure sqljiexiqi as
v_str  varchar2(4000);
v_sql  varchar2(4000);
v_sql1 varchar2(4000);
v_sql2 varchar2(4000);
v_sql3 varchar2(4000);
v_sql4 varchar2(4000);
v_sql5 varchar2(4000);
v_sql6 varchar2(4000);
v_sql7 varchar2(4000);
v_sql8 varchar2(4000);
v_sql9 varchar2(4000);
begin
dbms_output.enable(8000);
execute immediate 'truncate table tmp_table';
  forc in (select job_id, select_sql
              from bds.etl_job_info
            where length(trim(select_sql))
              and job_id = 'a') loop
  v_sql := 'explain plan set statement_id=''' || c.job_id || ''' for ' ||
            c.select_sql;
  execute immediate v_sql;
  for re in (select distinct object_name
                from plan_table
                where statement_id = c.job_id
                  and object_type = 'table') loop
    insert into tmp_table
      (job_id, select_sql, object_name)
    values
      (c.job_id, c.select_sql, re.object_name);
  end loop;
  commit;
  endloop;
  forc in (select job_id, select_sql
              from bds.etl_job_info
            where length(trim(select_sql)) > =4000
              and job_id ='sj_as_cm_mort_dtl_d') loop
  v_str  := 'explain plan setstatement_id=''' || c.job_id || ''' for ';
  v_sql  := substr(c.select_sql, 1,4000);
  v_sql1 := substr(c.select_sql, 1 * 4000 + 1, 4000);
  v_sql2 := substr(c.select_sql, 2 * 4000 + 1, 4000);
  v_sql3 := substr(c.select_sql, 3 * 4000 + 1, 4000);
  v_sql4 := substr(c.select_sql, 4 * 4000 + 1, 4000);
  v_sql5 := substr(c.select_sql, 5 * 4000 + 1, 4000);
    v_sql6:= substr(c.select_sql, 6 * 4000 + 1, 4000);
  v_sql7 := substr(c.select_sql, 7 * 4000 + 1, 4000);
  v_sql8 := substr(c.select_sql, 8 * 4000 + 1, 4000);
  v_sql9 := substr(c.select_sql, 9 * 4000 + 1, 4000);
  execute immediate v_str || v_sql || v_sql1 || v_sql2 || v_sql3 ||
                      v_sql4 || v_sql5 ||v_sql6 || v_sql7 || v_sql8 ||
                      v_sql9;
  for re in (select distinct object_name
                from plan_table
                where statement_id = c.job_id
                  and object_type = 'table')loop
    insert into tmp_table
      (job_id, select_sql, object_name)
    values
      (c.job_id, c.select_sql, re.object_name);
  end loop;
  commit;
  endloop;
end;
3、执行存储过程
  exec sqljiexiqi;
4、查询tmp_table表，得到sql中有哪些表
select * from tmp_table;
，